Insert for a rim of a spoked wheel for bicycle and respective spoked wheel for bicycle

ABSTRACT

An insert for the rim of a spoked bicycle wheel that has a spoke hole. The insert has a portion configured to abut against a spoke attachment element with an enlarged head and a holding element that prevents movement of the spoke attachment along said longitudinal axis of the spoke hole.

CROSS REFERENCE TO RELATED APPLICATION(S)

This application claims the benefit of Italian Patent Application No.102017000140052, filed on Dec. 5, 2017, which is incorporated herein byreference as if fully set forth.

FIELD OF INVENTION

The invention relates to an insert for a rim of a spoked wheel forbicycle. More particularly, the invention relates to an insert thatstabilizes the spoke in the rim. The invention also relates to a spokedwheel for a bicycle comprising such an insert. The wheel can be a frontwheel or a rear wheel on a mountain-bike or a roadster bicycle or aracing bicycle.

BACKGROUND

A spoked wheel for a bicycle comprises a rim, a hub and a plurality ofspokes extending between the hub and the rim, the tension of which mustpreferably be able to be adjusted at the hub and/or the rim.

In order to allow the adjustment of the tension, a first threading istypically provided at a first end portion of the spokes and a threadedhole is arranged at the hub or the rim. The threaded hole is madedirectly in the hub or rim, or in a spoke attachment element associatedwith the hub or rim. The second end portion of the spokes can beprovided with a second threading or with a head, for example rectangularor circular, housed in a suitable seat, for example hooked in a flangeof the hub or inserted in a bayonet coupling at the rim, as for exampledescribed in US 2007/0158996, which is discussed below.

Rims are known having a radially outer tyre coupling channel and aradially inner spoke attachment chamber. More in particular, such rimscomprise two side walls connected or joined at one end by a radiallyinner wall or lower bridge, and in an intermediate point by a radiallyouter wall or upper bridge or partition, so as to have a substantiallyinverted A-shaped cross-section. The radially outer portions of the sidewalls are typically provided with an edge configured to couple with abead of the tyre and form the tyre coupling channel with the upperbridge or partition, whereas the radially inner portions of the sidewalls form, with the lower bridge and the upper bridge, a spokeattachment chamber. Such a type of rim is illustrated in US2007/0158996.

A plurality of spoke attachment holes is made on the lower bridge of therim. Generally, the spoke attachment holes receive the spoke attachmentelement provided with a longitudinal cavity having a threading or with alongitudinal cavity having a shaped seat. The longitudinal length of thethreading of the longitudinal cavity of the spoke attachment element canbe equal to the longitudinal length of the threading of the spoke, orlonger to also allow the adjustment of the tension of the spoke bychanging the screwing depth of the spoke in the threaded longitudinalcavity of the spoke attachment element.

The spoke attachment elements are also called “nipples”, if they allowthe adjustment of the tension of the spoke, or “barrels” if they do notallow it.

Instead of a single spoke attachment chamber, two or more chambers canbe provided through one or more partition walls, extending substantiallyparallel to the upper bridge or substantially transversal to it. Eachwall (upper bridge, lower bridge, side walls and partition walls),furthermore, can be shaped in various ways, making an even considerablycomplex cross section of the rim.

The rims can be made from aluminum (typically by extrusion of a sectionbar) or from composite material (typically by compression molding).

The Applicant has concentrated its attention on rims made from compositematerial.

EP 3225384 A1, to the same Applicant, discloses a process formanufacturing a rim at least partially made from composite material. Themanufactured rim comprises a wall made from composite material and aplurality of perforated spoke attachment seats, the latter comprising ahole made in the wall and an amassment of structural fibers arranged ina surrounding area of the hole. The rim may further comprise an inserthaving a through hole, constrained to (preferably co-moulded with) thecomposite material at the perforated seat. The insert increases theresistance of the rim to the traction stresses by the spokes of thewheel. Moreover, the fact of constraining the insert to the compositematerial avoids frictional wear due to the sliding of the insert on thecomposite material.

US 2007/0158996 A1, to the same Applicant, discloses a rim in which theupper bridge comprises only the hole for the inflation valve of the tyre(and it is therefore also proper for the use with tubeless tyres). Sucha document also discloses a process aimed at making a spoked wheel forbicycle. Such a process comprises the step of inserting the spokeattachment element in the spoke attachment chamber through an opening(which can be the aforementioned hole or a different opening suitablymade) and guiding the spoke attachment element along the spokeattachment chamber towards and up to a respective spoke attachment hole.The spoke attachment element has a head adapted for being held insidethe spoke attachment chamber at the spoke attachment hole and a stemthat projects from the lower bridge in a radially inner directionthereof. The process comprises the step of inserting the stem of thespoke attachment element in the spoke attachment hole until the head isbrought into abutment on the lower bridge of the rim and the stem ismade to project from the lower bridge radially inside the rim (see forexample FIG. 9 of such a document).

US 2007/080577 A1 discloses a nipple for a bicycle wheel comprising ahead intended to abut on a radially inner wall of the rim and a stemcomprising a threaded portion intended to be screwed to a matchingthreaded portion made at the end of the spoke.

The Applicant has observed that in the aforementioned prior artdocuments the stems of the spoke attachment elements are typically sizedto project significantly from the rim in a radially inner directionthereof and the portion of stem projecting from the rim is typicallyshaped to allow the stem to be gripped by a suitable tool during themounting and the adjustment of the tension of the spoke. The latterprovision is necessary particularly in the cases in which the upperbridge of the rim is not perforated. In such cases, indeed, it is notpossible, during the mounting and the adjustment of the tension of thespoke, to hold the spoke attachment element at its head and it is thusnecessary to do so at the radially inner area with respect to the rim.

In some rims currently commercialized by the Applicant, the stemprojects from the rim by about 7 mm.

The Applicant has noted that, close to the lower bridge of the rim, andmore in particular at the areas in which the spokes are connected to thestems of the spoke attachment elements there are changes of diameterbetween the diameter of the stem and the diameter of the spoke. Suchchanges of diameter create turbulences during rolling.

The Applicant has observed that the lower bridge of the rim, and inparticular the size of its radius of curvature, greatly influences theaerodynamic behavior of the wheel with respect to front or side wind. Awheel with a lower bridge having a small radius of curvature (forexample equal to about 5.5 mm) has better performance with the frontwind whereas a wheel with a lower bridge having a greater radius ofcurvature (for example equal to about 9.5 mm) behaves better in case ofside wind.

U.S. Pat. No. 7,140,696 B1 discloses a wheel comprising a rim withnipples arranged entirely inside the spoke attachment chamber. In orderto screw the spokes on the nipples, a plurality of holes is made on theupper bridge of the rim.

The Applicant has observed that the wheel of U.S. Pat. No. 7,140,696 B1is not suitable for the use with tubeless type tyres.

According to the Applicant, the aforementioned turbulences, occurringprecisely close to the lower bridge of the rim, significantly andunpredictably change the expected aerodynamic behavior.

Therefore, there is a need to improve the aerodynamics of the wheels atthe lower bridge of the rim.

SUMMARY

The technical solution of the present invention is that of providing aninsert that allows the mounting and the tensioning of the spokes inbicycle wheels that, the structural strength being equal, have betteraerodynamic behavior than that of the wheels of the prior art and thatcan be used both with tyres provided with air chamber and with tubelesstype tyres.

The insert of the present invention provides a rim insert with a firstsurface portion configured to abut against an inner surface of the spokeattachment hole of the rim and a second surface portion configured toabut against an enlarged head of the spoke attachment to prevent themovement of the spoke attachment when said spoke attachment elementabuts against the second surface portion.

BRIEF DESCRIPTION OF THE DRAWINGS

The features and advantages of the invention will become clearer fromthe description of some preferred embodiments thereof, made withreference to the attached drawings, where:

FIG. 1 is a perspective view of a portion of spoked wheel for bicycleaccording to the present invention;

FIG. 2 is a perspective view, enlarged and in an axial section, of therim of the wheel of FIG. 1, taken at a spoke attachment hole;

FIG. 3 is an enlarged perspective view of a radially lower portion ofthe rim of FIG. 2;

FIG. 4 is an enlarged perspective view of an insert used in the rim ofFIGS. 2 and 3;

FIG. 5 is a perspective view of a component of the insert of FIG. 4;

FIGS. 6a-6d are perspective view in an axial section of the wheel ofFIG. 1, taken at a spoke attachment hole, in successive steps of makingand mounting of the wheel;

FIG. 7 is a perspective view of a first embodiment of a spoke attachmentelement used in the wheel according to the present invention;

FIG. 8 is a perspective view of the spoke attachment element of FIG. 7mounted on the wheel;

FIG. 9 is a perspective view of the spoke attachment element of FIG. 7with which a first embodiment of an adjustment tool for adjusting thetension of a spoke is coupled;

FIG. 10 is a cross section view of the spoke attachment element and ofthe tool shown in FIG. 9, the cross section being taken at the sectionplane S of FIG. 9;

FIG. 11 is a perspective view of a second embodiment of a spokeattachment element used in the wheel according to the present invention;

FIG. 12 is a perspective view of the spoke attachment element of FIG. 11mounted on the wheel;

FIG. 13 is a perspective view of the spoke attachment element of FIG. 11with which a second embodiment of an adjustment tool for adjusting thetension of a spoke is coupled;

FIG. 14 is a cross section view of the spoke attachment element and ofthe tool shown in FIG. 13, the cross section being taken at the sectionplane S1 of FIG. 13;

FIG. 15 is a perspective view of a third embodiment of a spokeattachment element used in the wheel according to the present invention;

FIG. 16 is a perspective view of the spoke attachment element of FIG. 15with which a third embodiment of an adjustment tool for adjusting thetension of a spoke is partially coupled;

FIG. 17 is a cross section view of the spoke attachment element and ofthe tool shown in FIG. 16, the cross section being taken at the sectionplane S2 of FIG. 16;

FIGS. 18-22 are perspective views in axial section of five variantembodiments of a spoke attachment element and of an insert used in thewheel according to the present invention, the sections being taken at aspoke attachment hole;

FIG. 23 is a perspective view of the insert of FIG. 22.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the present description and in the following claims, the terms“axial”, “axially” and similar terms refer to a direction substantiallycoinciding with or substantially parallel to the rotation axis of thewheel, the terms “radial”, “radially” and similar terms refer to adirection perpendicular to the rotation axis of the wheel and incidenton the rotation axis of the wheel, and the terms “circumferential”,“circumferentially” and similar terms refer to a circumferentialdirection around the rotation axis of the wheel.

In the rest of the present description and in the following claims, theterm “composite material” is used to indicate a material comprisingstructural fibers incorporated in a polymeric material. The structuralfibers are preferably selected from the group comprising carbon fibers,glass fibers, boron fibers, aramid fibers, ceramic fibers andcombinations thereof. The polymeric material can be thermoplastic orthermosetting.

The terms “axially inner” and “axially outer” and similar terms refer topositions respectively closer to, and farther from, a median transversalplane of the wheel, whereas the terms “radially inner” and “radiallyouter” and similar terms refer to positions respectively closer to, andfarther from, the rotation axis of the wheel.

The present invention relates, in a first aspect thereof, to an insertfor a rim of a spoked wheel for bicycle, comprising:

a first surface portion configured to abut against an inner surface of arim at a spoke attachment hole of the rim,

a through hole extending along a longitudinal axis and configured to becrossed by a spoke attachment element, and

a second surface portion configured to abut against an enlarged head ofthe spoke attachment element,

characterized in that it comprises at least one holding elementconfigured to prevent the movement of the spoke attachment element alongsaid longitudinal axis when said spoke attachment element abuts againstsaid second surface portion.

Advantageously, the provision of an insert having the aforementionedholding element prevents the spoke attachment element from moving alonga radially outer direction during the operations of attachment andtensioning of the spoke. Therefore, it is not necessary to make holes inthe upper bridge at every spoke attachment hole in order to hold thespoke attachment element in position during the aforementionedoperations, as conversely occurs in the wheel according to U.S. Pat. No.7,140,696 B1.

The insert of the invention can therefore be used in wheels intended toreceive both tyres provided with air chamber and tubeless type tyres.

Moreover, thanks to the provision of the aforementioned holding elementduring the mounting and the adjustment of the tensioning of the spoke,it is not necessary for the operator to grip the spoke attachmentelement by a tool. It is therefore possible to use a spoke attachmentelement which does not project radially from the rim internally withrespect to the rim, or which has a radially inner end portion whichprojects radially from the rim internally with respect to the rim by asegment having a reduced length, in particular shorter than or equal tothe diameter of the spoke at the spoke attachment hole. The worsening interms of aerodynamic behavior of the wheel due to the spoke attachmentelement is therefore null or substantially null. Indeed, even in thecase in which the aforementioned segment protrudes internally withrespect to the rim, it has a negligible length with respect to thedimensions of the spoke. In practice, such a segment does not generateadditional turbulences with respect to those generated by the spoke.

Advantageously, the insert also acts as a local reinforcement and as asupport for the spoke attachment element and allows a betterdistribution of the stresses on the rim caused by the tensioning of thespoke.

The insert of the invention can comprise, singularly or in combination,one or more of the following preferred features.

In a preferred embodiment of the invention, the insert comprises a mainbody on which a first through hole is made and an annular elementcoupled with the main body and having a second through hole arrangedcoaxially to the first through hole, the through hole of the insertbeing defined by the first and second through hole.

Preferably, said at least one holding element is defined by at least oneflexible portion of said annular element that projects cantilevered insaid second through hole.

Preferably, said flexible portion of said annular element is coated withrubber.

Preferably, said annular element is made from metallic material.

Preferably, said annular element is substantially flat and is co-moldedon said main body.

Alternatively, said annular element is substantially flat and is lockedon said main body through at least one covering layer comprising carbonfibers.

Preferably, at least one insulating layer comprising glass fibers isinterposed between said main body and said annular element in order toprevent that galvanic corrosion phenomena arises between the metallicmaterial of the aforementioned annular element and the compositematerial of the rim.

In a variant of the insert of the invention, said at least one holdingelement is defined by an O-ring arranged in a circumferential seatformed in a position adjacent to an undercut annular surface of saidinsert.

Preferably, said circumferential seat is defined at a first portion ofsaid insert comprising said first surface portion or at a second portionof said insert comprising said second surface portion. In both cases,the circumferential seat comprises an undercut radially outer annularsurface configured to prevent the movement of the O-ring in a radiallyouter direction and, possibly, an undercut radially inner annularsurface configured to prevent the movement of the O-ring in a radiallyinner direction.

In accordance with an alternative embodiment of the invention, theinsert comprises a pair of hooking arms that extend parallel to saidlongitudinal axis and each comprising a folded free end portion defininga respective holding element.

In this case the coupling between the annular element and theaforementioned main body is of the “snap” type.

In accordance with a further alternative embodiment of the invention,said annular element comprises a pair of hooking arms each having a freeend portion configured to couple with said main body. Also in this casethe spoke attachment element is locked on the insert with a hooking ofthe “snap” type.

In accordance with a further embodiment of the invention, the insertcomprises a main body on which a first through hole is made and anauxiliary body coupled with said main body and having a second throughhole arranged coaxially to said first through hole.

Preferably, the through hole of the insert is defined by the first andsecond through hole.

More preferably, said at least one holding element is defined by anO-ring arranged in a circumferential seat formed in said auxiliary bodyin a position adjacent to an undercut annular surface of said auxiliarybody.

In a second aspect, the invention relates to a spoked wheel for bicycle,comprising:

a rim made at least partially from composite material and provided witha plurality of spoke attachment holes,

a plurality of spokes coupled with the rim at said spoke attachmentholes,

a spoke attachment element arranged at a respective spoke attachmenthole,

at least one insert in abutment against an inner surface of said rim,

wherein said at least one insert is an insert according to the firstaspect of the present invention.

Such a wheel can advantageously comprise rims with the upper bridgeprovided or not provided with holes further than the hole for theinflation valve and can therefore be used both with tyres provided withair chamber and with tubeless type tyres.

Preferably, said spoke attachment element is partially inserted in saidspoke attachment hole and does not project radially from the riminternally with respect to the rim.

Alternatively, said spoke attachment element is partially inserted insaid spoke attachment hole and comprises a radially inner end portionthat projects radially from the rim internally with respect to the rimby a segment having a length shorter than or equal to the diameter ofthe spoke at said spoke attachment hole.

A benefit of the invention is obtained in the aerodynamic behavior ofthe wheel.

With reference now to FIGS. 1-5, reference numeral 100 wholly indicatesa first embodiment of a spoked wheel for bicycle according to thepresent invention.

The wheel 100 comprises a rim 10, a hub 20 and a plurality of spokes 30extending between the hub 20 and the rim 10. The tension of the spokes30 is adjusted at the rim 10 through spoke attachment elements 40 (FIGS.2 and 3).

The rim 10 is made at least partially from composite material.Preferably, the rim 10 is made entirely from composite material.

With reference to FIG. 2, the rim 10 comprises a radially outer tyrecoupling channel 12 and a radially inner spoke attachment chamber 14.

The rim 10 is preferably used with a tubeless type tyre (notillustrated).

The rim 10 is formed by two side walls 16 a connected or joined at aradially inner end by an inner circumferential wall or lower bridge 16b. The two side walls 16 a are further connected in an intermediatepoint by an outer circumferential wall or upper bridge (or partition) 16c, so as to have a substantially inverted A-shaped cross section (FIG.2).

The side walls 16 a comprise respective radially outer portions or fins16 d typically provided with a folded end 16 e. The fins 16 d form, withthe upper bridge 16 c, the tyre coupling channel 12. More in particular,the tyre, not illustrated for reasons of clarity, is mounted in the tyrecoupling channel 12 by inserting the beads thereof in the fins 16 d, thefolded ends 16 e acting to hold the beads in a per se known way.

The radially inner portions 16 f of the side walls 16 a form, with thelower bridge 16 b and the upper bridge 16 c, the spoke attachmentchamber 14.

The rim 10 comprises a pair of holes (not illustrated) for housing aninflation valve of the tyre (not shown). Such holes are madesubstantially coaxially in the upper bridge 16 c and in the lower bridge16 b.

The fins 16 d are subject to geometric and dimensional constraints bothdue to the need to hook the tyre, and due to the need to externallyprovide a suitable sliding surface of the brake pads. The upper bridge16 c is subject to the constraint, in the case of tubeless type tyre, ofmaking an airtight seal with the tyre and therefore of having only thehole for the valve. For tyres with air chamber, of course, such aconstraint does not exist and therefore further holes can be provided inaddition to the one for the valve.

On the other hand, the portions 16 f of the walls 16 a and the lowerbridge 16 b are not subject to particular geometric or dimensionalconstraints and can therefore be replaced by a single wall having across-section shaped like an arc of circle or by a plurality of walls soas to form a section of more complex shape than the one illustrated,possibly defining a plurality of spoke attachment chambers 14 (notillustrated).

The particular section illustrated in FIGS. 2 and 3 therefore has amerely illustrative and non-limiting purpose of the present invention.

The spoke attachment chamber 14 is provided with a plurality of spokeattachment seats 17 (FIG. 2), each of which comprising a spokeattachment hole 18 (FIG. 1).

The spoke attachment hole 18 is a non-threaded hole.

The spoke attachment seats 17 are illustrated as formed in the lowerbridge 16 b of the spoke attachment chamber 14, but they can also beformed in one or both of the portions 16 f of the side walls 16 a.

The spoke attachment seats 17 can be uniformly distributed along themedian plane of the rim 10. The number and the distribution of the spokeattachment seats 17 can vary greatly. For example, the seats 17 could begathered in groups of two or three or four and/or be made on a pluralityof planes, different from the median plane of the rim 10.

The spokes 30 are coupled with the rim 10 at the spoke attachment holes18 using spoke attachment elements 40, each arranged at a respectivespoke attachment hole 18.

The spoke attachment element 40 comprises a stem 42 configured to extendthrough the spoke attachment hole 18 and an enlarged head 44 having asize greater than that of the stem 42 and configured to be held insidethe spoke attachment chamber 14.

Preferably, each spoke attachment hole 18 has a substantially circularsection, but it could have a different shape, provided that it isconfigured to house the stem 42 of the spoke attachment element 40.

A first end portion 32 of a spoke 30 is attached to the spoke attachmentelement 40, the second end portion of the spoke 34 being attached to thehub 20 (FIG. 1).

The spoke attachment element 40 may or may not allow the adjustment ofthe tension of the spoke 30.

The spoke attachment elements 40 are preferably nipples (i.e. they allowthe adjustment of the tension of the spokes 30), but they could also bebarrels (i.e. they do not allow the adjustment of the tension of thespokes 30).

The following description refers to the case in which the spokeattachment elements 40 are nipples.

The spoke attachment elements 40 comprise a threaded through hole 46 ahaving a length such as to allow the screwing to different depths of thefirst end portion 32 of the spoke 30, which has a threading matchingthat of the threaded through hole 46 a to obtain the adjustment of thetension of the spoke 30.

The spoke attachment element 40 is partially inserted in the spokeattachment hole 18 and comprises a radially inner end portion 41 that,in the specific example illustrated herein, projects radially from therim 10 internally with respect to the rim 10 by a segment having alength shorter than or equal to the diameter of the spoke 30, measuredat the spoke attachment hole 18. More in particular, the aforementionedlength is shorter than or equal to the diameter of the first end 32 ofthe spoke 30.

In preferred embodiments of the present invention, such a length isshorter than or equal to about 2 mm.

The wheel 100 comprises a holding element 50 configured to prevent themovement of the spoke attachment element 40 along a radially outerdirection.

In a first embodiment of the wheel 100 illustrated in FIGS. 1-5 theholding element 50 is defined in an insert 60 arranged inside the spokeattachment chamber 14. The insert 60 is illustrated in FIG. 4.

As illustrated in FIG. 2, the insert 60 comprises a first surfaceportion 61 arranged inside the spoke attachment chamber 14 at the spokeattachment hole 18 and in abutment against an inner surface 14 a of thespoke attachment chamber 14. With reference to the mounting position ofthe insert 60, the first surface portion 61 is therefore a radiallyinner surface of the insert 60.

The insert 60 comprises a through hole 62 extending along a longitudinalaxis X, arranged coaxially to the spoke attachment hole 18 and crossedby the spoke attachment element 40 (FIGS. 2 and 3).

As illustrated in FIG. 3, the insert 60 also comprises a second surfaceportion 64, which acts as an abutment for the enlarged head 44 of thespoke attachment element 40, in particular for a radially inner abutmentsurface 48 of the enlarged head 44. The abutment surface 48 has a shapematching that of the second surface portion 64. In the example of FIGS.2 and 3, the abutment surface 48 and the second surface portion 64 arefrusto-conical in shape.

As illustrated in FIGS. 1 and 3, a sealing element 90, for example arubber element, is coupled with the rim 10 at the spoke attachment hole18. The sealing element 90 comprises a through hole in which theradially inner end portion 41 of the spoke attachment element 40 isinserted. The sealing element 90 has a shape matching that of theradially inner end portion 41 of the spoke attachment element 40.

With reference to the mounting position of the insert 60, the secondsurface portion 64 is therefore a radially outer surface of the insert60.

The through hole 62 is preferably defined centrally in the first surfaceportion 61 and in the second surface portion 64 of the insert 60.

The holding element 50 prevents the movement of the spoke attachmentelement 40 along the longitudinal axis X when the spoke attachmentelement 40 is in abutment against the second surface portion 64.

The insert 60 comprises a main body 65, on which the aforementionedfirst surface portion 61 and second surface portion 64 are made, and anannular element 67 coupled with the main body 65 and, in particular,substantially overlapping the main body 65.

The through hole 62 is defined by a first through hole 62 a formed inthe main body 65 and by a second through hole 62 b formed in the annularelement 67 coaxially to the first through hole 62 a.

The annular element 67 preferably consists of a substantially flatmetallic plate.

The holding element 50 is defined by a flexible portion 67 a of theannular element 67 that projects cantilevered in the through hole 62.

As illustrated in FIG. 5, the flexible portion 67 a faces towards thesecond through hole 62 b and is made flexible thanks to voids 67 b ofmaterial that define tongues 67 c facing towards the second through hole62 b.

The flexible portion 67 a has a coating 68 made from flexible material,for example rubber. The function of the rubber is both for holding themoulding resin, which must not pass between the annular element 67 andthe main body 65 during the moulding, and for generating friction withthe spoke attachment element 40 once mounted.

The annular element 67 can be co-moulded on a radially outer portion 65a of the main body 65 or, alternatively, it can be locked on theradially outer portion 65 a of the main body 65 through at least onecovering layer arranged above the annular element 67 and comprisingcarbon fibers.

Preferably, at least one insulating layer comprising glass fibers isinterposed between the main body 65 and the annular element 67.

The spoke attachment element 40 comprises a holding surface 49configured to operate in abutment against the holding element 50.

In FIG. 3 the holding surface 49 is defined at a radially outer endportion of a circumferential projection 49 a of the enlarged head 44 ofthe spoke attachment element 40.

The circumferential projection 49 a is arranged in a radially outerposition with respect to the abutment surface 48.

The circumferential projection 49 a has a diameter greater than that ofthe second through hole 62 b of the annular element 67.

In the mounting operation, the spoke attachment element 40 is insertedin the through hole 62 of the insert 60 until the abutment surface 48abuts against the surface portion 64 of the insert 60. During insertion,the circumferential projection 49 a of the enlarged head 44 folds theflexible portion 67 a until it goes past it. The flexible portion 67 athen takes again its undeformed configuration and holds the spokeattachment element 40 thanks to the abutment between holding surface 49and flexible portion 67 a (FIG. 3).

With reference to FIGS. 6a-6d , subsequent assembly steps of the wheel100 of FIGS. 1-5 are shown.

The wheel 100 made from composite material is typically built byarranging layers of carbon fibers impregnated of resin inside a mould.

The inserts 60 are positioned at the spoke attachment holes 18. Suchinserts 60 are coated with at least one perforated layer of carbon fiberin order to be held stationary inside the rim 10.

The inserts 60 are made from a material that has features of resistanceto fatigue and co-mouldability with the composite material. Suitablematerials are thermoplastic or thermosetting polymers, possiblyreinforced with fiber. However, it is also possible to use metallicmaterials. A particularly preferred material is the polyetherimide,commercialized with the name Ultem 2400 by Sabic, Riyadh.

During the moulding of the rim 10, in order to avoid the resins pluggingthe spoke attachment holes 18 and the through holes 62 of the inserts 60and infiltrating in undesired areas, an auxiliary element 70 is usedthat has the function of a plug (FIG. 6a ). The way of using theauxiliary element 70 is analogous to that described in EP 3225384 A1, tothe same Applicant.

The auxiliary element 70 is made from a material that has features ofdeformability, resistance to the moulding temperatures and pressures ofthe composite material and of anti-adherence to the composite material.A particularly preferred material is latex or soft silicone rubber, forexample a silicone having a Shore A hardness 50.

At the end of moulding the auxiliary element 70 is pulled out from itselongated portion 72 that faces towards the center of the rim 10, and itis thus extracted from the rim 10 (FIG. 6b ).

Subsequently, through the hole for the inflation valve (or from anauxiliary hole) the spoke attachment elements 40 are inserted in the rim10.

The spoke attachment element 40 has a screw 74 made from metal(typically steel). The screw 74 is screwed in the threaded through hole46 a, with the head 76 of the screw 74 projecting from the stem 42 onthe opposite side with respect to the enlarged head 44 of the spokeattachment element 40.

The spoke attachment element 40 with the screw 74 screwed thereto isinserted in the spoke attachment chamber 14 through the hole for theinflation valve (or through an auxiliary hole) and is taken with amagnet (as described in US 2007/0158996) at the through hole 62 of therespective insert 60, until the head 76 of the screw 74 inserts into thethrough hole 62 and comes out from the rim 10.

At this point the operator pulls the screw 74 radially inwards, untilthe spoke attachment element 40 is held in the insert 60 (FIG. 6c ) bymeans of the abutment between abutment surface 48 of the enlarged head44 of the spoke attachment element 40 and surface portion 64 of theinsert 60 and of the abutment between holding surface 49 defined in theenlarged head 44 of the spoke attachment element 40 and holding element50 defined in the insert 60.

The screw 74 is then unscrewed from the spoke attachment element 40 andit is possible to continue the mounting of the spoke 30 in the spokeattachment element 40, without it being necessary for the operator tohold the spoke attachment element 40 either while the screw 74 is beingunscrewed, or while the spoke 30 is being screwed.

In the case the spoke 30 breaks close to the first end 32, the spokeattachment element 40 remains in the through hole 62 of the insert 60.For its replacement it is sufficient to strike it with a punch and makeit come out from the hole for the inflation valve.

For the adjustment of the tension of the spoke 30 a suitable adjustmenttool 80 is used, like for example the one illustrated in FIG. 6 d.

The adjustment tool 80 comprises an elongated body 82, extending along alongitudinal axis Y and having a central longitudinal cavity 84 and alongitudinal through slit 86.

The central cavity 84 is configured to house the end portion 32 of thespoke 30. The slit 86 is configured to allow the housing of the endportion 32 of the spoke 30 in the central cavity 84.

The elongated body 82 comprises a grip portion 87 and a shaped endportion 88, extending along the longitudinal axis Y of the elongatedbody 82 and configured to couple with the stem 42 of the spokeattachment element 40.

The shaped end portion 88 has an outer bulk, defined on a planeperpendicular to the longitudinal axis Y of the elongated body 82,smaller than that of the grip portion 87 and smaller than the diameterof the spoke attachment hole 18 in which the stem 42 is inserted.

In this way, the shaped end portion 88 can insert inside the spokeattachment hole 18 and maneuver the stem 42 in rotation.

The shaped end portion 88 couples with the stem 42 of the spokeattachment element 40 through a surface having a shape matching that ofthe stem 42.

FIGS. 7-10, 11-14 and 15-17 respectively illustrate three variantembodiments of the spoke attachment element 40 and three respectivevariant embodiments of the adjustment tool 80.

In FIGS. 7-17 the components and the portions of the spoke attachmentelement 40 analogous or functionally equivalent to those of the spokeattachment element 40 of FIGS. 2 and 3 are indicated with the samereference numeral and reference is made to the relative description madeabove.

The stem 42 of the spoke attachment element 40 of FIGS. 7-10 comprises aplurality of longitudinal ribs 43, extending parallel to a longitudinalaxis Z of the spoke attachment element 40. In the non-limiting exampleillustrated herein, the ribs 43 are four, three of which have asubstantially identical circumferential extension, whereas the fourthhas a greater circumferential extension.

Housing seats 43 a for respective maneuvering appendages 89 of theshaped end portion 88 of the adjustment tool 80 are identified betweenthe ribs 43. The maneuvering appendages 89 project from the grip portion87 parallel to the longitudinal axis Y of the elongated body 82 and havea shape matching that of the housing seats 43 a.

In the illustrated non-limiting example, the housing seats 43 a and themaneuvering appendages 89 are four, and they have substantially anidentical circumferential extension (FIG. 10).

The maneuvering appendages 89 have for example a longitudinal extensioncomprised between about 2 mm and 4 mm.

The outer bulk of the maneuvering appendages 89 is substantially equalto that of the ribs 43 of the spoke attachment insert 40, which issubstantially equal (slightly smaller) to that of the spoke attachmenthole 18. In this way, the free space in the spoke attachment hole 18 isreduced when the spoke attachment element 40 is inserted therein. Thisreduces the problems caused by possible accumulation of dirt in thisfree space. On the other hand, the diameter of the adjustment tool 80 atthe maneuvering appendages 89 is sufficiently large as to ensure aneffective transfer of torque to the ribs 43 of the spoke attachmentinsert 40 without risks of breaking or deforming the aforementionedmaneuvering appendages 89.

The stem 42 of the spoke attachment element 40 of FIGS. 11-14,conversely, unlike that of the spoke attachment element 40 of FIGS.7-10, comprises an outer toothing 143, extending parallel to alongitudinal axis Z of the spoke attachment element 40. Preferably, theouter toothing 143 has a curved profile. In the non-limiting exampleillustrated herein the outer toothing 143 comprises six teeth and sixvalleys.

The shaped end portion 88 in this case comprises a toothed inner surface189, extending parallel to the longitudinal axis Y of the elongated body82. The toothed inner surface 189 has a shape matching that of the outertoothing 143 (FIG. 14).

The toothed inner surface 189 has for example a longitudinal extensioncomprised between about 2 mm and 4 mm.

The stem 42 of the spoke attachment element 40 of FIGS. 15-17,conversely, unlike that of the spoke attachment element 40 of FIGS. 7-10and that of the spoke attachment element 40 of FIGS. 11-14, comprises aninner toothing 243, extending parallel to a longitudinal axis Z of thespoke attachment element 40. Preferably, the inner toothing 243 has acurved profile. In the non-limiting example illustrated the outer innertoothing 243 comprises six teeth and six valleys.

The shaped end portion 88 comprises a toothed outer surface 289,extending parallel to the longitudinal axis Y of the elongated body 82.The toothed outer surface 289 has a shape matching that of the innertoothing 243 (FIG. 17).

The toothed outer surface 289 has for example a longitudinal extensioncomprised between about 2 mm and 4 mm.

FIGS. 18-23 illustrate five further embodiments of a spoked wheel 100for bicycle according to the present invention.

In FIGS. 18-23 the components and the portions of the wheel 100analogous or functionally equivalent to those of the wheel 100 of FIGS.1-5 are indicated with the same reference numeral and reference is madeto the relative description made above.

Unlike the wheel 100 of FIGS. 1-5, in the wheel 100 of FIG. 18 theholding element 50 is defined by an O-ring 350 arranged in acircumferential seat 369 formed in the insert 60.

The circumferential seat 369 is arranged adjacent to an undercut annularsurface 369 a of the insert 60. In particular, the circumferential seat369 is arranged in a radially inner position with respect to theundercut annular surface 369 a.

The circumferential seat 369 is arranged at the through hole 62 and isdefined in a first portion 61 a of the insert 60 comprising the firstsurface portion 61. The portion of abutment surface 64 is arranged in aradially outer position with respect to the undercut annular surface 369a.

The O-ring 350 is also arranged in a circumferential seat 342 formed inthe spoke attachment element 40. The circumferential seat 342 is formedon the stem 42 of the spoke attachment element 40.

In FIG. 18 the holding surface 49 is defined at the circumferential seat342 formed on the stem 42 of the spoke attachment element 40.

In order to make this embodiment it is necessary that in the mouldingstep of the rim 10 the area of the circumferential seat 342 is protectedfrom possible infiltrations of moulding resin. It must also be ensuredthat the geometry of the rim 10 is maintained.

For this reason, a suitable shaped protective insert is inserted in themould inside the through hole 62 of the insert 60. After moulding it canbe removed by breaking it.

The subsequent mounting steps of the wheel 100 comprise the mounting ofthe O-ring 350 on the spoke attachment element 40, the insertion of thespoke attachment element 40 with the O-ring 350 in the insert 60 andfinally the mounting of the spokes 30 as described above.

In the case of replacement of the spoke attachment element 40, theO-ring 350 is extracted from the circumferential seat 342 and replacedwith a new one.

Unlike the wheel 100 of FIGS. 1-5, in the wheel 100 of FIG. 19 theholding element 50 is defined by an O-ring 450 arranged in acircumferential seat 469 formed in the insert 60.

The circumferential seat 469 is arranged adjacent to an undercut annularsurface 469 a of the insert 60. In particular, the circumferential seat469 is arranged in a radially inner position with respect to theundercut annular surface 469 a.

The circumferential seat 469 is arranged at the through hole 62 and isdefined in a second portion 64 a of the insert 60 comprising the surfaceportion 64. The surface portion 64 is arranged in a radially innerposition with respect to the circumferential seat 469.

The O-ring 450 is also arranged in a circumferential seat 444 formed inthe spoke attachment element 40. The circumferential seat 444 is formedon the enlarged head 44 of the spoke attachment element 40.

The O-ring 450 has an outer diameter greater than the O-ring 350.

In FIG. 19 the holding surface 49 is defined at the circumferential seat444 formed on the enlarged head 44 of the spoke attachment element 40.

The insert 60 of this embodiment of the invention can be made by asintering process or by a 3D printing.

The wheel 100 of FIG. 20 differs from the wheel 100 of FIG. 19substantially in that the insert 60 of FIG. 20 is not in a single piecebut comprises a main body 561 and an auxiliary body 564.

A first through hole 562 a is made on the main body 561. The auxiliarybody 564 is coupled with a radially outer surface 561 a of the main body561 and has a second through hole 562 b arranged coaxially to the firstthrough hole 562 a.

The through hole 62 of the insert 60 is therefore defined by the firstthrough hole 562 a and by the second through hole 562 b.

The holding element 50 is defined by the O-ring 450 arranged in acircumferential seat 569 formed in the auxiliary body 564 in an adjacentposition (in particular, in a radially inner position) with respect toan undercut annular surface 569 a of the auxiliary body 564.

The O-ring 450 is also arranged in a circumferential seat 444 formed inthe spoke attachment element 40. The circumferential seat 444 is formedon the enlarged head 44 of the spoke attachment element 40.

In FIG. 20 the holding surface 49 is defined at the circumferential seat444 formed on the enlarged head 44 of the spoke attachment element 40.

In this embodiment the locking of the auxiliary body 564 in the mouldingstep can be carried out by overlapping one or more sheets of carbonfiber.

The wheel 100 of FIG. 21 differs from the wheel 100 of FIG. 19substantially in that the insert 60 of FIG. 21 comprises a pair ofhooking arms 650 that extend parallel to the longitudinal axis X (andtherefore in the radial direction) and each comprising a folded radiallyouter free end portion 651, defining a respective holding element 50.

The folded free end portion 651 holds the enlarged head 44 of the spokeattachment element 40 at a radially outer surface 644 thereof, which issubstantially flat.

In FIG. 21 the holding surface 49 is defined at the radially outersurface 644 of the enlarged head 44 of the spoke attachment element 40.

In this embodiment a “snap” coupling is obtained thanks to theelasticity of the material with which the insert 60 is made.

The wheel 100 of FIGS. 22 and 23 differs from the wheel 100 of FIGS. 1-5substantially in that the annular element 67 of the insert 60 of FIGS.22 and 23 comprises a pair of hooking arms 768 each having a foldedradially inner free end portion 768 a configured to couple with aradially inner surface of the main body 65 of the insert 60.

The holding element 50 of the insert 60 of FIGS. 22 and 23 is defined bythe flexible portion 767 a of the annular element 67 that projectscantilevered in the through hole 62.

As illustrated in FIG. 23, the flexible portion 767 a is defined by twoopposite tongues facing towards the through hole 62.

The flexible portion 767 a is arranged in a circumferential seat 444formed in the spoke attachment element 40. The circumferential seat 444is formed on the enlarged head 44 of the spoke attachment element 40.

In FIG. 23 the holding surface 49 is defined at the circumferential seat444 formed on the enlarged head 44 of the spoke attachment element 40.

Also in this embodiment it is advisable to ensure that there is nocontact between the carbon fiber of the rim 10 and the metallic materialof the annular element 67. It is also advisable to prevent that thereare infiltrations of moulding resin during the moulding of the rim 10both in the passage area of the spoke attachment element 40, and underthe flexible portion 767 a.

Of course, those skilled in the art can bring numerous modifications andvariants to the present invention as described above, in order tosatisfy specific and contingent requirements, all of which are in anycase within the scope of protection defined by the following claims.

In particular, it is possible to provide for any combination of thefeatures disclosed with reference to the embodiments and variantsdescribed.

For example, the upper bridge of the rim may or may not comprise furtherperforations in addition to that for the inflation valve of the tyre/airchamber.

Furthermore, it is possible to provide systems configured to avoid theunscrewing of the spoke attachment element 40 from the spoke 30 (due inparticular to vibrations). For example it is possible to use gluesbetween the threads of the threaded end portion 32 of the spoke 30 andthe threaded through hole 46 a or at the top of the threaded end portion32 of the spoke 30, and in particular in the threaded through hole 46 a,it is possible to insert a perforated ball 95, for example made fromnylon (as illustrated in FIG. 3).

The spoke attachment element 40 can also be made from aluminum.

What is claimed is:
 1. An insert for a rim of a spoked wheel forbicycle, comprising: a first surface portion configured to abut againstan inner surface of a rim at a spoke attachment hole of the rim, athrough hole extending along a longitudinal axis (X) and configured toreceive a spoke attachment element, and a second surface portionconfigured to abut against an enlarged head of the spoke attachmentelement, wherein said insert has at least one holding element configuredto prevent movement of said spoke attachment element along saidlongitudinal axis (X) when said spoke attachment element abuts againstsaid second surface portion.
 2. The insert according to claim 1,comprising a main body with a first through hole and an annular elementcoupled with the main body and a second through hole arranged coaxiallywith the first through hole, the through hole of the insert beingdefined by the first and second through holes, wherein said at least oneholding element is defined by at least one flexible portion of saidannular element that projects into said second through hole.
 3. Theinsert according to claim 2, wherein said flexible portion of saidannular element is coated with rubber.
 4. The insert according to claim2, wherein said annular element is made from a metallic material.
 5. Theinsert according to claim 2, wherein said annular element issubstantially flat and is co-molded on said main body.
 6. The insertaccording to claim 2, wherein said annular element is substantially flatand is locked on said main body through at least one covering layercomprising carbon fibers.
 7. The insert according to claim 2, wherein atleast one insulating layer comprising glass fibers is interposed betweensaid main body and said annular element.
 8. The insert according toclaim 1, wherein said at least one holding element is defined by anO-ring arranged in a circumferential seat formed in a position adjacentto an undercut annular surface of said insert.
 9. The insert accordingto claim 8, wherein said circumferential seat is defined at a firstportion of said insert comprising said first surface portion or at asecond portion of said insert comprising said second surface portion.10. The insert according to claim 1, comprising a pair of hooking armswith portions that extend parallel to said longitudinal axis (X) and endportions that are substantially perpendicular to said longitudinal axis(X) and that define a respective holding element.
 11. The insertaccording to claim 2, wherein said annular element includes a pair ofhooking arms, each arm having a free end portion configured to couplewith said main body.
 12. The insert according to claim 1, comprising amain body on which a first through hole is made and an auxiliary body iscoupled with said main body and has a second through hole arrangedcoaxially to said first through hole, the through hole of the insertbeing defined by the first and second through holes, wherein said atleast one holding element is defined by an O-ring arranged in acircumferential seat formed in said auxiliary body in a positionadjacent to an undercut annular surface of said auxiliary body.
 13. Aspoked wheel for bicycle, comprising: a rim made at least partially fromcomposite material and provided with a plurality of spoke attachmentholes; a plurality of spokes coupled with the rim at said spokeattachment holes; a spoke attachment element arranged at a respectivespoke attachment hole; and, at least one insert in abutment against aninner surface of said rim, wherein said at least one insert is an insertaccording to claim
 1. 14. The wheel according to claim 13, wherein saidspoke attachment element is partially inserted in said spoke attachmenthole and does not project radially from the rim internally with respectto the rim.
 15. The wheel according to claim 13, wherein said spokeattachment element is partially inserted in said spoke attachment holeand comprises a radially inner end portion that projects radially fromthe rim internally with respect to the rim by a segment having a lengthshorter than or equal to a diameter of the spoke at said spokeattachment hole.